1. Field of the Invention
The present invention generally relates to a surgical retraction instrument. More particularly, certain embodiments relate to a retractor for spinal surgery that allows for canted insertion of retraction components (blades) of the retractor and allows for independent movement of the retraction components.
2. Description of Related Art
A tissue retractor may be used during a surgical procedure to temporarily displace obstructing tissue and create a channel to a surgical target. The retractor may allow access to a surgical target while limiting an amount of dissection required to reach the surgical target. The retractor may be used to provide access to a spinal disc, a vertebra, and/or vertebrae during spinal surgery. The retractor may be used during minimally invasive spinal surgery.
A tissue retractor may include retractor components. Some of the retractor components, such as retractor blades, may be inserted into an incision made through a patient's skin. After insertion, a retraction mechanism may be engaged to increase a separation distance between retractor blades to retract tissue. Separation of the tissue by a retractor may allow a surgeon and/or surgical instruments unobstructed access to a site of interest while minimizing the requirement for dissection. Minimizing dissection may reduce tissue trauma, bleeding, recovery time, scarring, and patient risk that are associated with excessive dissection.
Retractor mechanisms that may be used in a surgical retractor instrument may include ratchet, screw or scissor mechanisms. Operation of the retractor mechanism may transmit force to retractor blades. The force separates the tissue into which the blades are inserted. Various retractors are disclosed in U.S. Pat. No. 6,712,795 to Cohen; U.S. Pat. No. 6,663,562 to Chang; U.S. Pat. No. 6,679,833 to Smith et al.; U.S. Pat. No. 6,659,945 to Ball et al.; U.S. Pat. No. 5,339,801 to Poloyko et al., each of which is incorporated by reference as though fully set forth herein.
Many retractors are composed of radio-opaque materials such as metal. The radio-opaque material may limit radiological imaging of a surgical site during a surgical procedure.
During some surgical procedures, it may be necessary to remove, exchange or replace one or more retractor components. Some retractors include blades that are fixed to a retractor mechanism. Some retractors include blades that cannot be removed and replaced while the retractor is in use. During some surgical procedures, the amount of retraction may need to be increased during a surgical procedure. Some retractors do not allow for extending an incision without completely releasing established retraction. During some surgical procedures, access to a surgical site from the skin of the patient may need to be made at an angle relative to the patient to allow for manipulation of tissue and/or insertion of an implant or stabilization system in a desired orientation. Some retractors cannot be easily canted so that excess separation with the retractor must be established to allow for manipulation of tissue and/or insertion of the implant or stabilization system in the desired orientation.